管理多个git版本库的小工具，可以在任意目录下执行git命令

add gita ll which displays summary of all repos, i.e., the old gita ls behavior. Meanwhile, gita ls only shows names of all repos, which is used by the bash auto completion script. gita ls <repo name> still shows the repo path.

change the superman mode to

gita super [repo-name(s)] <command/alias>

so that the command can be apply to any number of specified repos, or all repos if not specified.

add bash auto completion script

improve execution speed with async calls and by replacing all os.system calls with subprocess calls

change the pull sub-command to have optional arguments

gita pull [repo-name(s)]

add allow_all mode in the custom command configuration to apply the custom command to all repos if no repo is specified, like gita fetch and gita pull